And five per cent



C. F. SHERWOOD.

AGITATING MACHINE.

APPucAnoN man APR.28. 191sA Q7 She/72220,@

UNITED STATES PATENT OFFICE.

CHARLES F. SHERWOOD, OF SALT LAKE CITY, UTAH, ASSIGNOB, BY DIRECT AND MESNE ASSIGNMENTS, 0F NINETY PER CENT. TO GEORGE T. HANSEN, OF SALT LAKE CITY, UTAH, AND FIVE PER CENT. T0 THOMAS A. RYAN A N D FIVE PER GENT. T0 B. O. JONES, BOTH 0F DENVER, COLORADO.

AGITATING-MACHINE.

Specification of Letters Patent.

Patented Julie 14, 1921.

Application filed April 28, 15H9. Serial No. 293.28.

To all whom t may concern.' Be it known that I, CHARLES F. SHER Woon, a citizen of the United States, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented a certain new and useful Improvement in Agitating- Machines, of which the following is a full, clear, concise and exact description, reference being had to the accompanying drawincs, forming a part of this specification.

ily invention relates to the art of mixing or agitating. W'hile I shall describe the invention. with special reference to a particular embodiment and a articular art namely, mineral separation )y flotation, do not intend to limit the invention to the specific embodiments described nor to the particular art with which the said specific embodiments are concerned. The invention is peculiarly adapted to machines and devices through or in which a gritty material is handled or agitated and While the first and primary object is the provision of an improved protective lining or covering for the parts subject to the destructive erosion of the abrasive material which is treated, a further and more f'ar reaching object is to improve the fundamental operation. of mixing or agitating itself based upon the yielding or iinpressionable and resilient character of the surfaces which engage the medium to be mixed or agitated. I have discovered that in mixing or tating a fluid medium composed of con stitueuts of different inertia characteristics or different charactcristilfs of fluidity, for example a iinely divided solid such as a metal ore and a liquid suoli as Water or a mixture of liquids such as oil and water with which the herein described partiiular embodiments of my invention are concerned, the impressionable and resilient character of the agitating members or surfaces promotes a more intimate and more eflicacious mixture or mutual intermiugling of the constituent particles than has heretofore been attained by any of the devices of the prior art with which I am familiar. l shall define for the purposes of the following specification and claims a fluid medium as a mass or body of particles all of such dimensions and of such relative free- :loin of motion with respect to each other as to flow or move readil with respect to each other When subjecte to the action of a stirrer or agitator. I do not intend to limit the phrase solely to liquids, or gases or 'vapors or solutions or mixtures containing liqpids, gases or vapors.

llore iarticularly, my invention is es ecially app icable to agitating machines o the type commoniy employed in the oil flotation process of concentrating ores. As usually constructed, such machines comprise a casing usually having a separate metallic lining, within which is arranged a mechanically operated impeller or agitator, the function of the machine being to continuously agitate a contained liquid which carries a finely pul vel-ized ore such a gold bearing quartz. The liquid carrying the quartz consists of water withA a relatively small percentage of oil, and in some instances an acid reagent such as sulfuric acid.

The oil has a preferential ailinity for the metallic or metalliferous parts of the ore, which phenomenon is taken advanta e of in raising the ore particles to the sur ece by flotation. The general practice is to create a froth or foam bearing the oil treated metallic or metalliferous particles which froth or foam may be brushed off or removed` 'ith this particular phase of theflotation process my invention, is not immediately concerned as my invention relates to the stage of mining or agitating and not the froth removal.

Agrit-ating machines of the general type, with which my invention is concerned, function to secure an intimate commingling of the ulverized ore with the flotation liquid by t oroughly agitating the pulp at a high speed, with the result that the continual impingement of the grit particles of the ore against the interior parts of'the machine, particularly the metallic lining and the impeller soon destroys these parts by abrasion and the machine must either be repaired or replaced.

My invention provides first a rotective coi @ring for the metallic lining an the other metallic parts exposed to the impingement of the ore particles, which protective covering is of such a nature that the hard par ticles in the pulp do not abrade or :wt this away, and second, an irripressiouablf.l Uastic lil 2 1,.,sif3

:.iii'lnuc wliiili liiiimt the particles (if Fig. i2 is :i transverse sei'tiiiz'izil View of the kniipiairiiiii [lint :in extiriiiiiily han@ metallic iiiiiw miiiiiil lic more capii. i of withstandmili-r ifi. iiisiiii. 'Vini-mi ilw amil wie Elin" iigitzitirigj i'liiiiiiliifi" il l im lll) lli)

adapted to arrest the circulatory motion of the pulp or froth as it emerges from the agitating chamber 9 `and permit it to settle quiescently into the chamber 1,3 from whence it flows out through tliebpening 21 and down into the separating box 3.

A. sha ft 2l from the motor 7, extends down into the agitating chamber and has connec' tion through the coupling 25 with the im peller shaft 26. This impeller shaft supports an upper agitator 27 and a lower agitator 28, which preferably take the form of a series of radiating arms, four in number, and which are rotated at a relatively high speed by the motor 7 to secure a thorough agitation of the pulp. The lower impeller arms 28 are relatively short in order to just clear a series of baliles 29 which extend inwardly from the walls of the casing 4, as clearly shown in Fig. 2. The upper impeller arms 27 extend outwardly with just suicient clearance for safety between the e1 .s thereot` and the interior surface of the chamber 9. The lower impeller arms 28 are sli htly lished or curved as clearly shown in an upward propulsion to the pul in addition to the circulatory agitation o the ulp.

The pulp enters at the lower en'd o? the agitation chamber 9 through the conduit 30, which leads up from a relatively low point in the separating box 3. By the operation of the agitator a circulation of pulp is built up between the separating box 3 and the agitator 1, the pulp` flowing up through the conduit 30 into the agitating chamber 9, out over the top thereof into the trough 13, and out through the port 21 back into the separating box 3. When the pulp is discharged into' the separating iox 3 after agitation, the metalliferous matter is held in suspension by the adhesion of the oil particles While the gaugue or refuse precipitates to the bottom of the separating box, where it is recirculatcd for the further extraction of metals.

'It will be immediately apparent that a very destructive erosion of any unyiel ding surface,

subject to the impingement of the rock and metal particles `is bound to ensue from the violence of the agitation and the speed of rotation of the impellers, which ranges 'from 500 to 1,00() r. p. m. Replaceable metallic linings have been the only expedient hereto fore practised for taking care of this condition, but obviously the replacing of these -linings involves such inconvenience and expense in addition to the loss in shutting down the machine, that they have become practically intolerable. These, furthermore, are impracticable for protecting the surfaces of the impellers.

The resilient linin which I propose using preferably consists o a layer of rubber Tlf.` ot' approximately or il" thickness, which is vulcanized about the interior of the agil ating chamber.. 9. The projecting battles 29 must ig. 2, to impart also be protected with a rubber' covering. which may be accomplished by stretching the main lining 32 to conform to the sha pc of tbc bullies and vulcanizing the rubber in place, or by vulcanizing separate strips to thc surfaces of the baffles and then vulcanizing the strips to the main lining 32 to form a homogcneous lining, or by any other suitable Vmethod. The interior of the discharge duct with the impeller shaft 26, as indicated )at 3G. U

T he rubber sheathing for the impe-ller arms may be applied as previously stated, or it may be molded in the proper shape prior to being vulcanized to the impellers and there after vulcanized to the tubular sheath inclusing the impeller shaft 2G.

The etlicacy of this protective layer of rubber may be illustrated by reference to :i specitic instance in which an agitating muchine so protected was employed for agitat ing a pulp consisting of quartz containing metallic particles in the percentage of one of solid to three ot water. and after months of handling pulp of this character showed no visible signs of abrasion. With the usual metallic construction, this severe service would have necessitated a renewal of the lining at least every few months. l found also that for the expenditure ot :1 given amount of energy the vield of ore was markedly increased. I attribute this to two fundamental causes,-Iirst, the lowcr cocllicient of friction caused by the elimination of wearing and greater freedom of uiolion and second to 'the greater relative motion between particles and more thorough appli cation of the oil to the metal particles caused by the greater area of contact which is sccured when a particle embedsitseli mol 111- tariiy in the impressionable resilient sur acc y of the rubber. A further utility o f this rubber lining is that of protecting the interior of the agitator from the corrosive action of the acids commonly added to the In Fig. 3 I have shown my invention applied to an air agitated flotation machine. In this arrangement compressed air injected into thc pulp, is used as the agitating agency.

The casing comprises the main cylindrical shell 41, forming an agitating chamber 42. and the enlarged cupshaped portion 43, forming a pulp collecting trough. or launder 44. At its lower end the casing 4l carries a conical chamber 15, secured thereto bythe lUO flanges ttl. A comprennent air nuzzlc it? e tt'ntls up through the ronic'nl member 45, :ind opt'm intu u Central ngitating tube 4S, Whit'h is supprutetl in thtJ ngitating Chamber 42 hy wings 49 extending inward from the;I rinsing- LL als t'it'nrly shown in Fig. 5. A tletieting :1) 51 surniounts thtx agitnting tubo 4T :intl unf'titlns to lt'th't't the ngitutell nm. ut puh). :is it is impt'ilt'fl upward through the tulw 48. (uit over the tup (if the tube und bark into the mitin zigituting rhumht'r 42. The L'nhirget Casing 43 is prnritlt'tl with u small inwnrelly t'xteniliug thing@ utlliztrt'nt thv finnr nt' tht' truugjh it, und o upf'ruting with this1 thing@ is n i'inf.r 54. which is Huppm'ttul :ihm-e thi' Hum' ut' tht'. truugh hy :i iluwn-tnriu'il thingy' 5.7. the'rt'hy forming un :umuhir e'muluit 5t! in thtA bottom ut' the trough. Tht' migo ut' the' ring' 54 is Sparer! troni tht' thingie 55! tu ultimi :in unnuhir opening: troni tht' ronduit iutu tht' truuggl':l This trimming is 'ovt'rtul hy :t ring ut thin fuhrii- ."it' whie'h sustains tinx froth :intl ltvt'lls it mit nl tin' t'muluit Utl. .\ir iunior t Hiight prosr suriis mhnittml tu tht' 'uneluit 5H, unil this uil'. issuing through tin' tuhrif' ring- Titi. hlmrs tht' truth uit nl' tht' tup ut' tlux trough 'tt tust :is it ui'tth' luu'n :itung tiu ini-lined 'fm1' Ht' the tiuugh. i'lum tht' lip cit' thi' :igituting' fhzfilnlwr 5t A\ t'ingf 5H is mlpi'mrtt'el in tht' upper part ui thv t'uhlrgi'cl using EL tur tht' giurimw mi pimemtiug tht' truth from t'uiliitf: luu'h infn thv :initiating c'hunilu'r Yti. Th1' truth ruilt't'tingl rvi't'liturh' :intl tht' nir 'ulutinr Hkistviu tur vinti-grin); tht' ugitutiun rhzimht'r with pulp .'irt' not Shown :is thru' hurt' nu liri't't lwuriug upon the' prt'st'nt inttltitm.

it peruliur action which grt'zttlt' improves the'. operation ur :it'tiuu f mixingr ur agituting.

During the lt'hitive mutiun between the ruhlwr surfnet' :intl tht' tluiil iufm. tht' purtin cles 0f Uil tu tw rlistrihutiui mnu' intu wn tart with the ruhher surfant'. sio'thut for ene'h nuntiuft nt' n giuhuit' of uil with the ruhu'r there ib u wetting; nf tht' ruhht'i' suri'zice with oil, wht'rehy for a hriel' pt'riwl mi" tinux :it lt'zxst tht're is :l film nt' rail nginn n putt of the surt'zut'. Thereufttlr It't us usufruit' that i partido of nieta] ur uu'tullit'euuuu im" utriiits tht' surt'ntft- :it tht' puint wlu'rt' tin' tilni uf uil is formed. The ensuing mutant lc'twt'en thtI ln'atvy particle uf nit'tnl nr urs', mus't'u n rf'hitivt'ty gft-enter writting nt tht! surfant' ut tht' purtit'le with the' nil lwr'uuezi' tlu' ruhlu'r surface. permits tht1 particlv to @miami itself nimnentarily. .ts .suon :is the' impuut ut' thi' pnrtit'lt' is tziltvn up the partiti? im' thmwu uti' litri-:inw nl' tht* resilient t'hui'zwtt'r' it tht Vul)` hr1'. The snrtzit't' is thus st'it cit-:ming uml :tlwnyw rt'utly to re'pent thtj nptzut imi,

l tinfl that thv nil inw u tt'ntlonvlv tu :ulht'ru quilt' firmly tu thu rubber suxtzir." until it is taken up by tht' nir'tul or ure' iaith-hm'. :mii thif4 pln'nuint'nnn assists furtht'r in thv hi'ttt'r tiistrihutiun of the' nil tu tht' nu'tnl nr orte purtirh's although this is not tht' smh' reason is l hure :iliuvn ineliuntt'tl for the" impl-tired t'tiit'it'au'y hut is nu'tt'ly :l furtht'r t'm'nrzihh' iu'tion in the pruftifi' of :lgitatiuagr pulp :incl wil, This Snl'tut'c is. primarily rosiiitnt dnd prt'fc'rbly ruhhl'r. ihuugh nut not'wsnrily su, ,its any utht'r suizillh' yit'ltlingg nuitcriui might` he t'uipluyt'ii. lurtJ ruuht'r may he unt-th tu* :in v Sltitnliia temiiiinni'inn tit' inhiber :ltirl fuhr-iv.

I lu mit wish tu limit the inventiun tu the ust' m" ruhher. li'Vhile to my prescrit knowir-lgi' thia` is the only Suhtuntr Whirh will .'t' c'ure the tlesire'e'l t'tt'rrt ur attenti; l intenti tu int'lutit' dnt-h substitut ur f'quivultfnts as t'nilmtly the t'liurzxi'tm'istif's Whir'h are rtl quil-oel tu summa the` funihunentnl :u'tion whit-h l hurt' ilistlnst'il. l t'niiiilug tht' phrase' ruiilit'r liltt1 i' l3nt proleutivv liner of rubber covering' tlm interior Uf saisi 11g-hating chamber. :i rulibm' mating mln'urugf ille exposed surfacing nf sziill bullies. :mil :i Similar Ijullbei' wavering mulilvd about :inici agitator urnls :1nd sheathinr .will :lg'illxlm shaft tu prvwnt abrasion :uml vou'nsun im' miil liquid emulsion.

livw in Suid aginling e-imml'm'. :mel :i pmwtiw lining nl l'illllwl' vulmluizeld nimm llnsinful-vs ul' Siliil vlmmzmr :mil said lmlllfg 

